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TRX70 TRX90 TRX125 TRX200 TRX250
TRX300 TRX350 TRX400 TRX420 TRX450
TRX500 TRX650 TRX680 TRX700



Engine Turns Over But Fails to Start

No fuel
Dirt in fuel line or filter
Fuel will not pass through fuel valve
Fuel pump inoperative/restricted
Tank vent plugged
Carb starter circuit
Engine flooded
Low compression (high cylinder leakage)
No spark (Spark plug fouled)

Engine Does Not Turn Over

Dead battery
Starter motor does not turn
Engine seized, rusted, or mechanical failure
Recoil components damaged

Engine Runs But Will Not Idle

Restricted carburetor pilot system
Carburetor misadjusted
Choke not adjusted properly
Low compression
Crankcase breather restricted
Air filter restriction

Engine Idles But Will Not Rev Up

Spark plug fouled/weak spark
Broken throttle cable
Obstruction in air intake
Air box removed (reinstall all intake components)
Incorrect or restricted carburetor jetting
ETC switch limiting speed
Reverse speed limiter limiting speed
Carburetor vacuum slide sticking/diaphragm damaged
Incorrect ignition timing
Restricted exhaust system
Cam Lobe worn

Engine Has Low Power

Spark plug fouled
Cylinder, piston, ring, or valve wear or damage (check compression)
PVT not operating properly
Restricted exhaust muffler
Carburetor vacuum slide sticking/diaphragm damaged
Dirty carburetor
Cam lobe worn

Piston Failure - Scoring

Lack of lubrication
Dirt entering engine through cracks in air filter or ducts
Engine oil dirty or contaminated

Excessive Smoke and Carbon Buildup

Excessive piston-to-cylinder clearance
Worn rings, piston, or cylinder
Worn valves, guides or seals
Restricted breather
Air filter dirty or contaminated

Low Compression

Decompressor stuck
Cylinder head gasket leak
No valve clearance or incorrectly adjusted
Cylinder or piston worn
Piston rings worn, leaking, broken, or sticking
Bent valve or stuck valve
Valve spring broken or weak
Valve not seating properly (bent or carbon accumulated on valve area)
Rocker arm sticking


ETC or speed limiter system malfunction
Fouled spark plug or incorrect plug or plug gap
Carburetion faulty - lean condition
Intake / Exhaust system air leaks
Ignition system faulty:
Spark plug cap cracked/broken
Ignition coil faulty
Ignition or kill switch circuit faulty
Ignition timing incorrect
Sheared flywheel key
Poor connections in ignition system
System wiring wet
Cam lobe worn or Valve sticking
Lean condition

Related Honda TRX Searches:

  • 1986-1987 TRX 70, TRX70
  • 1993-2005 TRX 90, TRX90
  • 2006-2009 TRX 90, TRX 90EX, TRX 90X
  • 1985-1986 TRX 125, TRX 125
  • 1987-1988 TRX 125, TRX125
  • 1984 TRX 200, TRX200
  • 1986-1988 TRX 200SX, TRX200 SX
  • 1990-1991 TRX 200 91-97 TRX 200D Type II
  • 1985-1987 FourTrax (Four Trax) 250, TRX250
  • 1987-1988 TRX 250X, TRX250X, TRX250 X
  • 1986-1989 TRX 250R, TRX250R, TRX250 R
  • 1991-1992 TRX 250X, TRX250 X
  • 1997-2004 Recon TRX250 TM, TRX250 TE
  • 2001-2005 TRX 250EX, TRX250 EX
  • 2005-2011 Recon TRX250, TRX250TM, TRX250TE
  • 2006-2009 TRX 250 EX, TRX 250X
  • 1988-1994 FourTrax 300 (TRX 300, TRX 300 FW 4x4)
  • 1993-2000 TRX 300EX
  • 1995-2000 Honda TRX300 (TRX 300), TRX300FW (TRX 300 FW) Fourtrax ATV
  • 2001-2006 TRX 300EX, TRX300 EX
  • 2007-2009 TRX 300EX, TRX 300X
  • 1986-1987 FourTrax TRX350 4x4
  • 1987-1989 Foreman TRX 350D, TRX350D, TRX350 D
  • 2000-2003 Rancher TRX350FM, TRX350TM, TRX350FE, and TRX350TE
  • 2004-2006 Rancher TRX350TE, TRX350TM, TRX350FE, TRX350FM
  • 1995-2003 Foreman TRX400FW
  • 1999-2004 TRX 400EX, TRX400 EX
  • 2004-2007 Rancher TRX400FA, TRX400FGA, TRX400
  • 2005-2009 TRX 400EX, TRX 400X
  • 2007-2010 Rancher TRX420, TRX420FE, TRX420FM, TRX420TE, TRX420TM, TRX420FPE, TRX420FPM
  • 2009-2010 Rancher AT TRX420FA, TRX420FPA, TRX420
  • 1998-2004 Foreman TRX450S, TRX450FM, TRX450ES, TRX450FE
  • 2004-2009 TRX 450R, TRX 450ER, TRX450 E
  • 2001-2004 Foreman Rubicon 500 TRX500FA, TRX500 FA
  • 2005-2009 Foreman Rubicon TRX500 FA, TRX500 FGA
  • 2005-2011 Foreman TRX500, TRX500FE, TRX500FM, TRX500TM, TRX500FPE, TRX500FPM
  • 2003-2005 Rincon TRX650FA
  • 2006-2011 Rincon TRX680FA,  TRX680FGA, FA/FGA
  • 2008-2009 Honda TRX700 X X (TRX 700 XX, TRX700XX)

Honda TRX Service Manuals, Download Repair Manuals, Troubleshooting Manual, Factory Service Manual, Handbook, Book, Shop Manual, Worshop Guide, Owner's Manual